Cycladic Flat Roof

The flat, whitewashed roof is one of the defining features of village architecture in the Cyclades, the Aegean island group that includes Santorini, Mykonos, Naxos and Paros. Box-like houses with flat roofs step up hillsides, with domed churches rising among them.

Why flat?

Several conditions favoured flat roofs in the Cyclades:

• Low rainfall - the islands are dry, so a flat roof drains adequately if it is kept in good repair.
• Scarce timber - long timber for pitched roof structures was hard to obtain on small, treeless islands, so spans were kept short.
• Strong winds - the summer meltemi winds favour compact, low-profile buildings.
• Water collection - flat roofs act as catchments that feed rainwater into cisterns.

Construction

Traditional flat roofs were built over short spans of timber beams or, on some islands, masonry vaults, with layers of smaller sticks or reeds, and a thick layer of earth or local volcanic and clay materials, sloped gently to spouts. The surface was finished with lime. On Santorini, many houses were built as barrel vaults or carved into the soft volcanic rock of the caldera, and the air-filled pumice in the surroundings provides insulation.

Whitewash

Houses and roofs are coated with white lime wash, renewed regularly. The lime keeps surfaces cooler in strong sun, and its use is also linked to keeping roofs clean so that collected rainwater is usable. Whitewashing has an aesthetic role as well, and on islands like Santorini it is now part of planning rules.

Domes

Churches are usually covered with small domes on drums. On Santorini the domes of churches in villages such as Oia are often painted blue, producing the familiar white-and-blue image of the islands.

Earthquakes and conservation

The islands are seismic. The 1956 earthquake caused major damage on Santorini and was followed by emigration and later by building restrictions. A preservation programme from 1976 converted many abandoned cave houses into guest houses and hotels. Today, most new buildings use reinforced concrete flat roofs with modern waterproofing, finished white to match the tradition.